This KB article details the issue: Effectively, there is a 32-kilobyte (KB) 'packed data' memory limit for the rules on each folder in the Inbox or in a public folder, each inbox rule takes about 660 bytes, therefore the maximum number of rules is 40-50 rules per folder, and the more rules the user has, the slower performance they will receive in Outlook. Users that add in too many rules not only have Outlook slow down because the rules have to fire off and process the rules before the user actually sees the message in their Inbox, but also having too many rules causes Outlook to slow down in general. Outlook has a limited (32kb) memory space allocated for rules. This may take a long time with a large mailbox, and during that time system performance for the user will be degraded, but once the indexing has been completed, performance will be improved.Ī not so common problem but one worthy to not are users that have a lot of Inbox or Folder 'Rules' in Outlook experience slowdown of Outlook. In the case where Indexing never seems to be completing, delete the index and choose to reindex the entire mailbox.

You may find that the system never finishes indexing messages ( ), that typically indicates that the index is corrupt, however while an index is corrupt, the Indexing service is still attempting to index Outlook, so not only is your index not getting updated, but the system is chewing up system cycles to continuously index the system and never completes. While indexing is being performed, expect system performance to be degraded. Solution: To check to see if indexing may be a performance problem, check the Indexing Status in Outlook, see if Outlook is indictating that Indexing is being performed.

Microsoft activesync outlook 2010